//! Simple unit tests about the control groups system.
use cgroups::{Cgroup, CgroupPid, Hierarchy, Subsystem};
use cgroups::memory::{MemController, SetMemory};
use cgroups::Controller;
use std::collections::HashMap;

#[test]
fn test_tasks_iterator() {
    let h = cgroups::hierarchies::auto();
    let h = Box::new(&*h);
    let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
    let cg = Cgroup::new(h, String::from("test_tasks_iterator"));
    {
        // Add a task to the control group.
        cg.add_task(CgroupPid::from(pid)).unwrap();

        use std::{thread, time};
        thread::sleep(time::Duration::from_millis(100));

        let mut tasks = cg.tasks().into_iter();
        // Verify that the task is indeed in the control group
        assert_eq!(tasks.next(), Some(CgroupPid::from(pid)));
        assert_eq!(tasks.next(), None);

        // Now, try removing it.
        cg.remove_task(CgroupPid::from(pid));
        tasks = cg.tasks().into_iter();

        // Verify that it was indeed removed.
        assert_eq!(tasks.next(), None);
    }
    cg.delete();
}


#[test]
fn test_cgroup_with_relative_paths() {
    if cgroups::hierarchies::is_cgroup2_unified_mode() {
        return
    }
    let h = cgroups::hierarchies::auto();
    let h = Box::new(&*h);
    let mut relative_paths = HashMap::new();
    relative_paths.insert("memory".to_string(), "/mmm/abc/def".to_string());
    let cg = Cgroup::new_with_relative_paths(h, String::from("test_cgroup_with_prefix"), relative_paths);
    {
        let subsystems = cg.subsystems();
        subsystems.into_iter().for_each(|sub| match sub {
            Subsystem::Pid(c) => {
                let p = c.path().to_str().unwrap();
                let rel_path = p.trim_start_matches("/sys/fs/cgroup/pids");
                assert_eq!(rel_path, "/test_cgroup_with_prefix")
            },
            Subsystem::Mem(c) => {
                let p = c.path().to_str().unwrap();
                let rel_path = p.trim_start_matches("/sys/fs/cgroup/memory");
                assert_eq!(rel_path, "/mmm/abc/def/test_cgroup_with_prefix")
            },
            _ => {}, 
        });
    }
    cg.delete();
}

#[test]
fn test_cgroup_v2() {
    if !cgroups::hierarchies::is_cgroup2_unified_mode() {
        return
    }
    let h = cgroups::hierarchies::auto();
    let h = Box::new(&*h);
    let cg = Cgroup::new_with_relative_paths(h, String::from("test_v2"), HashMap::new());

    let mem_controller: &MemController = cg.controller_of().unwrap();
    let (mem, swp, rev) = (4 * 1024 * 1000, 2 * 1024* 1000, 1024 * 1000);

    let _ = mem_controller.set_limit(mem);
    let _ = mem_controller.set_memswap_limit(swp);
    let _ = mem_controller.set_soft_limit(rev);

    let memory_stat = mem_controller.memory_stat();
    println!("memory_stat {:?}", memory_stat);
    assert_eq!(mem, memory_stat.limit_in_bytes);
    assert_eq!(rev, memory_stat.soft_limit_in_bytes);

    let memswap = mem_controller.memswap();
    println!("memswap {:?}", memswap);
    assert_eq!(swp, memswap.limit_in_bytes);

    cg.delete();
}